Rotary machine

ABSTRACT

This invention is a rotary internal-combustion engine in which a piston can reciprocate in a cylinder, and the reciprocation is translated into rotational movement by cams respectively on the piston and the stator casing; lateral loads are not transmitted from the piston to the cylinder to provide the output torque because the piston is mounted to slide on a guide or spoke which is itself fast with the output shaft.

United States Patent 1 91 Maw 1 1 Nov. 25, 1975 15 1 ROTARY MACHINE 1,832,575 11/1931 Palmer 74/55 [75] In entor: Eliahou Maoz, Vaduz, Liechtenstein 2,807,248 9/1957 Maloney 123/44 E [73] Assignee: Setec Societe destudes Techniques FOREIGN PATENTS OR APPLICATlONS Ansta", Vaduz Liechtenstein 19,666 8/1910 United Kingdom 44 E 202,035 8/1923 United Kingdom 123/44 E [22] Filed: Apr. 6, 1973 Appl. No.; 348,618

[30] Foreign Application Priority Data Feb. 22, 1973 United Kingdom 8797/73 Feb. 27, 1973 United Kingdom 9582/73 [52] U.S. Cl 123/44 E; 123/8.31; 123/8.49 [51] Int. Cl. l. F02B 57/06; F02B 57/08 [58] Field of Search 123/44 E, 43 C; 91/494, 91/495; 92/58 [56] References Cited UNITED STATES PATENTS 879,512 2/1908 Braunwalder 123/44 E Primary Examiner-Clarence R. Gordon Attorney, Agent, or FirmOblon, Fisher. Spivak, McClelland & Maier [57] ABSTRACT This invention is a rotary internal-combustion engine in which a piston can reciprocate in a cylinder, and

the reciprocation is translated into rotational movement by cams respectively on the piston and the stator casing; lateral loads are not transmitted from the piston to the cylinder to provide the output torque because the piston is mounted to slide on a guide or spoke which is itself fast with the output shaft.

17 Claims, 17 Drawing Figures US. Patent Nov. 25, 1975 Sheet 1 of9 3,921,601

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US. Patent Nov. 25, 1975 FIG. /7

ROTARY MACHINE This invention relates to rotary machines, for example rotary internal combustion engines.

According to the invention. an engine or other reciprocating machine comprises a -piston and a cylinder block capable of rotation together in relation to a stator, and cam means relating the reciprocating movement of the piston (or cylinder block) to the rotational movement of the piston/cylinder block combination, the piston (or cylinder block) being mounted on, or in, a guide which carries the lateral loads of the reciprocating piston (or cylinder block).

Certain previously-proposed rotary machines com prise a stator casing, a cylinder block capable of rotation in the stator casing and having cylinder bore means defining one or more working chambers closed at one end by the casing, piston means reciprocable in the cylinder bore means and cam means to which the piston means is operatively coupled to convert reciprocatory motion of the piston means into rotary motion of the output drive. A rotary output drive is taken from the cylinder block, and the required torque is transmitted by virtue of the pistons acting on the side walls of the cylinder bores.

This has the disadvantage that the piston seals and cylinder bore walls must withstand the high lateral loadings necessary to transmit the output torque, in addition to performing their normal pressure sealing function.

However in a machine according to the present invention, the two aforesaid and generally incompatible functions, i.e., the torque-transmitting and sealing actions, are carried out separately from each other.

This is achieved by the mounting of the piston on the guide which acts in a manner similar to that of the wellknown and well-proved connecting rod used in conventional intemal-combustion engines.

Thus there are no problems to be solved in designing such a piston and guide arrangement, nor are there problems in the piston and cylinder sealing arrangements since they only have to fulfil their primary function of establishing a seal.

The piston has been described above as sliding on or in the guide, but it is theoretically possible for the cylinder block to slide on, or in, the guide.

Whichever arrangement is used, the output drive is taken from the guide to avoid the torque transmitting loads being carried by the piston and cylinder seals.

The cylinder block may be also fast with the guide so that the seals do not even have to carry the relatively small loads necessary to rotate the cylinder block and so do not transmit any torque at all.

The load-carrying guide (or guides in a multicylinder machine), preferably takes the form of a spoke rigidly coupled to an output shaft and extending transversely (i.e., radially or chordally) of the axis of rotation of the machine, the, or each, piston having sliding engagement with its spoke for relative movement longitudinally of the spoke.

The output drive may comprise a shaft running through the centre of the engine and having the spokes fast therewith, and the stationary casing in this case surrounds the cylinder block and closes the outer ends of the cylinder bores. Alternatively, however, the spokes which are fast together, may also be fast to the cylinder block, by means of the tie bars, the output shaft being 2 coupled either to the spoke assembly or to the cylinder block.

The casing may alternatively extend through the centre of the engine, with the spokes extending inwardly from an annular member surrounding the cylinder block, with a similar possibility as above of fastening the spokes-cylinder block assembly to make one single unit, and coupling the output shaft either to the annular member or to the cylinder block.

These and many other variations are possible, as illustrated by the following description of some embodiments of the invention, given by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a radial cross-section of one internal combustion engine in accordance with the invention;

FIG. 2 is an axial section of the engine of FIG. 1;

FIG. 3 is an exploded, perspective view of the major components of the engine of FIGS. 1 and 2;

FIG. 4 is a viewsimilar to FIG. 1 of another embodiment of the invention wherein the spokes are chordally arranged and are mounted on the arms of a spider integral with the output shaft;

FIG. 5 is a view similar to FIG. 1 of yet another embodiment of the invention, wherein chordally directed cylinders and pistons are employed and the spokes are radially directed;

FIG. 6 is a view of yet another embodiment of the invention having six pistons working on a four-stroke cycle;

FIG. 7 is a view of yet another embodiment of the invention employing an eight cylinder engine;

FIG. 8 is a view of yet another embodiment wherein the pistons are linked for following the profile of a cam by an endless chain;

FIG. 9 is a view of yet another embodiment of the invention being adapted for a two-stroke operation;

FIG. 10 shows yet another embodiment of the present invention adapted for a six cylinder engine wherein gudgeon pins of opposed piston pairs are connected by rigid links;

FIG. 11 shows yet another embodiment of the present invention adapted for a two cylinder engine wherein the pistons are coupled by a rigid link;

FIG. 12 is a view of yet another embodiment of the present invention wherein the links of a piston coupling arrangement between adjacent pistons are flexible;

FIG. 13 shows another embodiment of the present invention wherein the pistons are interconnected by rigid links for maintaining cam followers in contact with a cam profile;

FIG. 14 is a view of an alternative spoke drive wherein two parallel offset spokes are arranged outside the center line of the pistons and are interconnected by a yoke to the piston;

FIG. 15 is a view of an engine in which the cylinder block is rigidly coupled to the spoke assembly by tie bars;

FIG. 16 is a view of yet another embodiment of the invention wherein the rotary thrust transmitting spokes project radially inwardly; and

FIG. 17 is a diagrammatic elevation of an engine installation seen in side elevation and partially in section.

The engine shown in FIGS. 1 to 3 is designed as a four-stroke internal combustion engine. It comprises a central drive shaft 1 extending through the centre of the engine and having four radially projecting spokes Id at right angles to each other. Slidably engaged over each spoke is a piston 2 having piston rings 2a and 3 working in a cylinder bore, of which four are provided in a freely rotatable cylinder block 3. The block 3 is mounted in a stationary outer casing 4 having inlet and outlet ports, A and B. The block is sealed to the casing 4 by gas sealing and oil scraper rings 3a.

The end walls of the casing are formed with endless track cam grooves 5 of the generally elliptical shape shown in FIG. 1. These cam grooves receive bearing mounted cam-followers 7 carried at the projecting outer ends of gudgeon pins 6 which are each fast with one piston and extends through elongated slots 31 in the spokes 1a. Ball bearings are provided at 9 between the cylinder block and the casing, and at 8 between the drive shaft and the casing. A sparking plug 10 is mounted in the casing opposite the ports A and B. An oil pump 11 mounted on an end wall of the casing provides for circulation of oil forthe inner rotational parts of the engine, through an oil cooler (not shown in FIGS. 1 to 3) and an auxiliary takeoff 12 is provided for driving a distributor, fuel pump, fan or other auxiliary assemblies.

In operation, ignition takes place when the outer end of one cylinder bore is opposite the spark plug 10. The combustion stroke is completed after some 90 of rotation, followed by exhaust (through port B) in the next quadrant, induction (through port A) in the next and compression in the final quadrant. There are thus four, four-stroke cycles, one for each cylinder and piston, in each revolution of the drive shaft.

In the combustion stroke, the piston 2 is driven radially inwards of its cylinder bore, interaction between the cam 5 and gudgeon pin cam follower 7 causing the piston 2 and cylinder block 3 to rotate about the axis of the shaft 1. This rotational motion is imparted to the drive shaft 1 through the radial spoke 1a. This means that the cylinder block 3 itself plays no part in transmitting drive, but merely follows freely the rotation of the pistons 2 and drive shaft 1. Thus, the mutually sliding surfaces of pistons 2 and cylinder bores are only required to carry out their pressure sealing function, and the small side loads required to carry round the cylinder blocks 3. The main torque transmitting function is performed by the mutually sliding surfaces of the pistons 2 and the spokes 1a. These surfaces are removed from the combustion chamber area, and are internally lubricated, and cooled.

Such an engine may also operate as a diesel engine, replacing the spark plug 10 by a fuel injector, or as a steam driven (external combustion) engine. Apart from the aforesaid action of relieving the piston seals and cylinder bore walls of the high lateral loadings and removing the main torque transmitting means from the combustion chamber area, the advantages of the engine in simplicity and efficiency rely particularly on the conventional reliable and wellproved pistons and sealing elements, the relatively small number of moving parts, the absence of internal gearing, valve mechanism and conventional flywheel. In the main concept, the engine is self-balancing and free from any eccentric rotating parts and its maintenance is relatively easy, noting particularly that the cam tracks are readily accessible for repair or replacement. Overall, the engine is easy to manufacture and of low cost. The stationary casing of the engine is preferably air-cooled but may also be water-cooled. The external shape of the cylinder block is shown as part spherical which is a preferred feature, but it may alternatively be cylindrical.

Some of the many constructional variants which are feasible within the scope of the invention are illustrated in the remaining drawings in which, as far as possible, 1 like reference numerals are used to indicate correworking on a four-stroke cycle, each piston 2 performs one extra reciprocation between completion of the exhaust stroke and the commencement of induction. This spare stroke may simply provide a cooling period. or

may be employed e.g. for additional pumping/compressing, combined with adequate transfer ports. The

cam 5 in this case has three lobes. As an alternative, a part of the cam 5 associated with the spare stroke, may be provided with a larger dwell to increase e.g. the pumping action if used.

FIG. 7 shows aneight-cylinder engine which has two diametrically opposed firing positions, the cam 5 hav- 1 ing four lobes or top dwell positions. This cam form may also be used in two banks'of four pistons each, phased at 45 to each other.

In FIG. 8 in which the spokes 1a are not shown for the sake of clarity, the pistons 2 are linked together and constrained to follow the profile of cam 5 by an endless chain 14 running on rollers 15 around the cam profile. I v The cam 5 may also be an external double-track in which the endless chain 14 is running.

FIG. 9 shows, diagrammatically, a version of the engine adapted for two-stroke operation. Two cylinder bores have working pistons P1 and P2 and communicate only with ports C and D, while the other two cylinder bores are blanked off at their outer ends and have pumping pistons P3 and P4 as well as side ports to communicate only with ports A, B and E.

In operation, working piston P1 is fired at top dead centre by sparking plug 10 and is driven down its bore and round to port D, where the cylinder bore exhausts. Then it passes port C, where an air/fuel charge is drawn into the cylinder bore, and compressed ready for ignition when it reaches top dead centre again opposite sparking plug 10. During continued rotation,pumping piston P3 receives an air/fuel charge at port A and carries it round to port B, compressing the charge in the process. At port B, the compressed charge passes through an interconnecting passage to port C, whence.

the pre-compressed charge is passed into the cylinder bore of working piston Pl. When pumping piston P3 reaches port E again, any residual excess pressure in the cylinder bore is relieved, and air enters the bore.

During the opposite half-cycle working piston P2 duplicates the functions of working piston P1, and pumping,

piston P4 duplicates the functions of pumping piston P3. In this case, the pumping pistons may be larger than the working pistons.

FIG. 10 shows a six-cylinder engine in which the gudgeon pins 6 of opposed piston pairs 2 are interconnected by rigid links 16, which are slotted over theirl central regions so that the links 16 may pass freely through each other. The internal cam 5 is three-lobed and of constant breadth, so that the followers 7 at opposite ends of each link 16 maintain positive contact with the cam surface.

FIG. 11 shows a two cylinder engine, in which the pistons 2 are coupled together by a rigid link 16. As an alternative, the two pistons 2 may be formed as a unitary double-ended piston body. An engine of this layout may operate on a two-stroke cycle as described in FIG. 9. Also cam 5 may be of circular form with an offset centre.

FIG. 12 shows a piston coupling arrangement in which the links 17 between adjacent pistons 2 are flexible for use especially with an irregular cam profile.

A method of achieving this is by telescopic ram assemblies having internal coil springs 18 which compress and expand.

FIG. 13 shows another form of linked piston arrangement, in which the pistons 2 are interconnected by rigid links 17 for maintaining the cam followers 7 in contact with the cam profile.

In FIG. 14 an alternative method is shown of a spoke drive, in which two parallel offset spokes 1a are arranged outside the centre-line of the pistons 2, interconnected by a yoke 23 coupled to the piston 2, the spokes having sliding engagement with the yoke 23. The spokes 1a are rigidly coupled to flanges 24 fast with the drive shaft (not shown).

FIG. 15 shows an engine in which the cylinder block 3 is coupled rigidly to the spoke 1a assembly by tie bars 19, which cancel or reduce drastically the lateral loads on the piston seals 2a and cylinder bore walls as well as the journal loads on bearings 9 shown in FIG. 2. These bearings 9 then may not be required. The tie bars 19 could in a modification pass through the piston centres, being provided with sealing elements. The output shaft 1 coupled in FIG. 15 to the spoke la assembly could also be coupled only to the cylinder block 3. These methods of linking the spokes 1a to the cylinder block 3 and coupling the output shaft 1 either to the spoke la assembly or to the cylinder block 3, apply equally to external spokes 1a as shown in FIG. 16.

FIG. 16 illustrates one possible form of engine in which the rotary thrust-transmitting spokes la project radially inwardly. The fixed part 4 is located at the centre of the engine assembly, to close the inner ends of the cylinder bores in the cylinder block 3, and the annular member lb carries inwardly projecting spokes 1a and encloses the piston 2 and cylinder block 3 assembl FIG. 17 shows an engine installation with an oil cooling system. The engine casing 4 is mounted in a duct 20 and cooled by an axial flow fan 21. Cooling oil is circulated through an external oil cooler 22.

It is seen from the foregoing description and accompanying drawings, that a great many combinations and variations are possible within the scope of the present invention, and it is clear that many constructional features of various embodiments are interchangeable. It is also clear that whenever a specific combination is unbalanced, the balancing may readily be achieved by coupling two or more similar banks phased at a proper angle to each other. The design of the cam profile 5 as well as the number of cam-tracks 5 and/or followers 7 6 employed in external combustion engines, such as steam engines and in other rotary machines. I What I claim as my invention and desire to secure by letters patent is:

.1. A rotary machine comprising:

a stator; a piston; a cylinder block; an outwardly extending piston rod guide being fixed 10 to an output shaft of said machine;

said piston and said cylinder block being capable of rotation together relative to said stator; said piston being reciprocably movable within said cylinder block; 15 a cam on said stator;

a cam follower on said piston; said cam and said cam follower relating said reciprocable movement of said piston within said cylinder to said rotational movement of said piston and pis- 20 ton cylinder block combination; and

said piston in its reciprocable motion within said cylinder being slidable over said piston rod guide which is received therein, whereby said piston rod guide carries the lateral loads of said reciprocating piston.

are to suit the particular requirements of an individual 2. A machine as claimed in claim 1, in which the cam follower comprises a roller on a skirt portion of said piston.

3. A machine as claimed in claim 1, which has a number of cylinders defined in the block and a piston in each cylinder.

4. A machine as claimed in claim 3 in which each cylinder is closed by the stator.

5. A machine as claimed in claim 1, including an output drive member which is fast with the guide.

6. A machine as claimed in claim 1 in which the guide extends radially of the axis of rotation.

7. A machine as claimed in claim 1 in which the guide extends chordally of the axis of rotation.

8. A machine as claimed in claim 1, in which the cam comprises an endless track cam surface.

9. A machine as claimed in claim 1 in which the cam follower is on a member which extends through a slot in the corresponding guide.

10. A machine as claimed in claim 3 in which the pistons are coupled together through rigid links.

11. A machine as claimed in claim 3 in which the pistons are coupled together through telescopic links.

12. A machine as claimed in claim 3 in which there are at least one pair of pistons, each of which pairs consists of two pistons a fixed distance apart and reciprocable on a common axis.

13. A machine as claimed in claim 12, in which there are at least two pairs of pistons, each pair consisting of two pistons held a fixed distance apart by a rigid link, one link extending through an aperture in the other link.

14. A machine as claimed in claim 3 in which an output shaft extends through the centre of the machine with each guide extending radially outwards from it, and in which the stator comprises a casing surrounding the piston and cylinder combination.

15. A machine as claimed in claim 3 in which there are at least two pistons and guides, all the guides being fast together.

16. A machine as claimed in claim 1, including means for providing cooling and lubricating oil to the loadcarrying surface of the guide.

3 ,9 2 l ;60 1 7 8 i i l 17. A machine as claimed in claim 1, arranged to opton arranged to a pre-compress a charge for the workerate as an internal-combustion engine on a two-stroke ing piston.

cycle, including for each working piston a pumping pis- 

1. A rotary machine comprising: a stator; a piston; a cylinder block; an outwardly extending piston rod guide being fixed to an output shaft of said machine; said piston and said cylinder block being capable of rotation together relative to said stator; said piston being reciprocably movable within said cylinder block; a cam on said stator; a cam follower on said piston; said cam and said cam follower relating said reciprocable movement of said piston within said cylinder to said rotational movement of said piston and piston cylinder block combination; and said piston in its reciprocable motion within said cylinder being slidable over said piston rod guide which is received therein, whereby said piston rod guide carries the lateral loads of said reciprocating piston.
 2. A machine as claimed in claim 1, in which the cam follower comprises a roller on a skirt portion of said piston.
 3. A machine as claimed in claim 1, which has a number of cylinders defined in the block and a piston in each cylinder.
 4. A machine as claimed in claim 3 in which each cylinder is closed by the stator.
 5. A machine as claimed in claim 1, including an output drive member which is fast with the guide.
 6. A machine as claimed in claim 1 in which the guide extends radially of the axis of rotation.
 7. A machine as claimed in claim 1 in which the guide extends chordally of the axis of rotation.
 8. A machine as claimed in claim 1, in which the cam comprises an endless track cam surface.
 9. A machine as claimed in claim 1 in which the cam follower is on a member which extends through a slot in the corresponding guide.
 10. A machine as claimed in claim 3 in which the pistons are coupled together through rigid links.
 11. A machine as claimed in claim 3 in which the pistons are coupled together through telescopic links.
 12. A machine as claimed in claim 3 in which there are at least one pair of pistons, each of which pairs consists of two pistons a fixed distance apart and reciprocable on a common axis.
 13. A machine as claimed in claim 12, in which there are at least two pairs of pistons, each pair consisting of two pistons held a fixed distance apart by a rigid link, one link extending through an aperture in the other link.
 14. A machine as claimed in claim 3 in which an output shaft extends through the centre of the machine with each guide extending radially outwards from it, and in which the stator comprises a casing surrounding the piston and cylinder combination.
 15. A machine as claimed in claim 3 in which there are at least two pistons and guides, all the guides being fast together.
 16. A machine as claimed in claim 1, including means for providing cooling and lubricating oil to the loadcarrying surface of the guide.
 17. A machine as claimed in claim 1, arranged to operate as an internal-combustion engine on a two-stroke cycle, including for each working piston a pumping piston arranged to a pre-compress a charge for the working piston. 